The invention concerns a process and a device for manufacturing extruded frozen confectionery with contrasting colourings and flavours defining a spiral, intended to fill family portions or "bulk" portions or pots or moreover for the manufacture of frozen lollies.
A device is known, for example from European Patent Application Publication No. 0 293 022, for filling portions of frozen confectionery containing a sauce or a syrup with which a contrasting design is produced in a double spiral or double concentric circles by means of a hollow rotating shaft placed axially in a tube and comprising lateral openings, while the tube comprises a central deflector element in the vicinity of the outlet delivery tube. The hollow shaft produces a pattern consisting of concentric circles of syrup which the deflector divides into two sub-patterns.
According to U.S. Pat. No. 3227103, for example, two pastry doughs are extruded, each through delivery tubes defining a spiral inscribed in a circular contour, so as to manufacture cakes of the "Swiss rolls" type. Such a device does not allow two frozen compositions to be co-extruded in the form of a spiral inscribed in a circle with correct definition of the contour of the spiral pattern, since it creates preferential flows which distort this pattern by reason of the high friction in the delivery tube in the form of a spiral and at the center of the pattern in relation to the periphery.